Probe systems and methods for testing a device under test

ABSTRACT

Probe systems and methods for testing a device under test are disclosed herein. The probe systems include an electrically conductive ground loop and a structure that is electrically connected to a ground potential via at least a region of the electrically conductive ground loop. The probe systems also include nonlinear circuitry. The nonlinear circuitry is configured to resist flow of electric current within the ground loop when a voltage differential across the nonlinear circuitry is less than a threshold voltage differential and permit flow of electric current within the ground loop when the voltage differential across the nonlinear circuitry is greater than the threshold voltage differential. The methods include positioning a device under test (DUT) within a probe system that includes an electrically conductive ground loop and nonlinear circuitry. The methods also include selectively resisting and permitting electric current flow within the ground loop and through the nonlinear circuitry.

RELATED APPLICATION

This application claims priority to U.S. Provisional Patent ApplicationNo. 62/930,959, which was filed on Nov. 5, 2019, and the completedisclosure of which is hereby incorporated by reference.

FIELD OF THE DISCLOSURE

The present disclosure relates generally to probe systems and methodsfor testing a device under test.

BACKGROUND OF THE DISCLOSURE

Probe systems may be utilized to test the operation of a device undertest (DUT). In specific examples, the DUT may include a semiconductordevice, and the probe system may be configured to electrically test theoperation of the DUT, such as by providing a test signal to the DUTand/or by receiving a resultant signal from the DUT.

In some configurations, one or more ground loops may be at leastpartially defined by the probe systems. The one or more ground loops mayintroduce electrical noise into a testing environment of the probesystems, which may decrease an accuracy of tests performed by the probesystems. Thus, there exists a need for improved probe systems andmethods for testing a device under test.

SUMMARY OF THE DISCLOSURE

Probe systems and methods for testing a device under test are disclosedherein. The probe systems include an electrically conductive ground loopand a structure that is electrically connected to a ground potential viaat least a region of the electrically conductive ground loop. The probesystems also include nonlinear circuitry. The nonlinear circuitry isconfigured to resist flow of electric current within the ground loopwhen a voltage differential across the nonlinear circuitry is less thana threshold voltage differential. The nonlinear circuitry also isconfigured to permit flow of electric current within the ground loopwhen the voltage differential across the nonlinear circuitry is greaterthan the threshold voltage differential.

The methods include positioning a device under test (DUT) within a probesystem that includes an electrically conductive ground loop andnonlinear circuitry. The methods also include resisting electric currentflow within the ground loop, with the nonlinear circuitry, when avoltage differential across the nonlinear circuitry is less than athreshold voltage differential. The methods further include permittingelectric current flow within the ground loop and through the nonlinearcircuitry when the voltage differential across the nonlinear circuitryis greater than the threshold voltage differential.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic illustration of examples of a probe systemaccording to the present disclosure.

FIG. 2 is a schematic illustration of examples of a probe systemaccording to the present disclosure.

FIG. 3 is a schematic illustration of an example of nonlinear circuitry,in the form of a diode pack, that may be utilized in probe systems,according to the present disclosure.

FIG. 4 is a less schematic illustration of examples of probe systemsaccording to the present disclosure.

FIG. 5 is a plot illustrating current and resistance as a function ofvoltage for nonlinear circuitry in the form of a diode pack, accordingto the present disclosure.

FIG. 6 is a flowchart depicting examples of methods of testing a deviceunder test utilizing probe systems, according to the present disclosure.

DETAILED DESCRIPTION AND BEST MODE OF THE DISCLOSURE

FIGS. 1-6 provide examples of probe systems 10 that may perform methods200, according to the present disclosure. Elements that serve a similar,or at least substantially similar, purpose are labeled with like numbersin FIGS. 1-6, and these elements may not be discussed in detail hereinwith reference to each of FIGS. 1-6. Similarly, all elements may not belabeled in each of FIGS. 1-6, but reference numerals associatedtherewith may be utilized herein for consistency. Elements, components,and/or features that are discussed herein with reference to one or moreof FIGS. 1-6 may be included in and/or utilized with any of FIGS. 1-6without departing from the scope of the present disclosure.

In general, elements that are likely to be included in a particularembodiment are illustrated in solid lines, while elements that areoptional are illustrated in dashed lines. However, elements that areshown in solid lines may not be essential and, in some embodiments, maybe omitted without departing from the scope of the present disclosure.

FIGS. 1-2 are schematic illustrations of examples of probe systems 10,according to the present disclosure, that may be utilized to test adevice under test (DUT). As illustrated in FIGS. 1-2, probe systems 10include a plurality of structures 20, including a first structure 21 anda second structure 22. First structure 21 is electrically connected to aground potential via a structure ground conductor 30 in the form of afirst structure ground conductor 31. Similarly, second structure 22 iselectrically connected to the ground potential via structure groundconductor 30 in the form of a second structure ground conductor 32.

As also illustrated in FIGS. 1-2, probe systems 10 include anintermediate ground conductor 40 that electrically interconnects firststructure 21 and second structure 22. Intermediate ground conductor 40may be electrically connected to the ground potential via firststructure 21 and first structure ground conductor 31. Intermediateground conductor 40 also may be electrically connected to the groundpotential via second structure 22 and second structure ground conductor32.

As further illustrated in FIGS. 1-2, probe systems 10 also includenonlinear circuitry 50, which also may be referred to herein as anonlinear impedance device 50. As used herein, the phrase “nonlinearcircuitry” is utilized to indicate one or more circuit elements thatcollectively exhibit a nonlinear current vs. voltage curve. As discussedin more detail herein, electric current flow through the nonlinearcircuitry is low, or negligible, for voltage drops across the nonlinearcircuitry that are less than a threshold voltage drop. However, forvoltage drops across the nonlinear circuitry that are greater than thethreshold voltage drop, the electric current flow through the nonlinearcircuitry increases substantially. An example of nonlinear circuitry 50includes a diode pack 68, examples of which are disclosed herein.Additional examples of nonlinear circuitry 50 include a power transistorwith included voltage-sensitive device, a power MOFSET with includedvoltage-sensitive device, and/or a transient voltage suppressor (TVS).Examples of the nonlinear current vs. voltage curve are illustrated inFIG. 5 and discussed in more detail herein.

Nonlinear circuitry 50 may be positioned, within probe system 10, suchthat first structure 21, first structure ground conductor 31, secondstructure 22, second structure ground conductor 32, intermediate groundconductor 40, and nonlinear circuitry 50 together and/or at leastpartially define a ground loop 150. Ground loop 150 also may be referredto herein as a continuous loop of electrically conductive material 150and/or as an electrically conductive ground loop 150.

Each of the components of ground loop 150 may be defined by anelectrically conductive material, such as a metal. However, ground loop150 may not be defined by perfect electrical conductors and instead mayinclude, or may be referred to herein as including, a plurality ofimpedances. As examples, first structure ground conductor 31, theconnection between first structure ground conductor 31 and firststructure 21, and/or the connection between first structure groundconductor 31 and the ground potential each may have and/or define agenerally small, but finite, corresponding electrical impedance.Additionally or alternatively, second structure ground conductor 32, theconnection between second structure ground conductor 32 and secondstructure 22, and/or the connection between second structure groundconductor 32 and the ground potential each may have and/or define agenerally small, but finite, corresponding electrical impedance.Additionally or alternatively, intermediate ground conductor 40, theconnection between intermediate ground conductor 40 and first structure21, and/or the connection between intermediate ground conductor 40 andsecond structure 22 each may have and/or define a generally small, butfinite, corresponding electrical impedance. Additionally oralternatively, the ground potential may be provided by a facilitiesground conductor 140, which may have and/or define a generally small,but finite, corresponding electrical impedance.

During operation of probe systems 10, the probe system and/or groundloop 150 thereof may be positioned within an environment that mayinclude a magnetic field M. The presence of magnetic field M may inducean electric current 80 flow within ground loop 150, and this electriccurrent flow may produce and/or generate electrical noise. Theelectrical noise may increase noise in and/or may decrease an accuracyof electrical tests performed by probe system 10.

However, probe systems 10, according to the present disclosure, thatinclude nonlinear circuitry 50 within ground loop 150 may decrease, ormay significantly decrease, a magnitude of electric current 80 thatflows within the ground loop. This decrease in electric current flow maydecrease, or significantly decrease, the electrical noise generated bythe electric current flow, thereby permitting probe systems 10,according to the present disclosure, to perform higher accuracy and/orlower noise tests when compared to prior art probe systems that definecorresponding ground loops but that do not include nonlinear circuitry50 within the corresponding ground loops.

FIG. 3 is a schematic illustration of an example of nonlinear circuitry50, in the form of a diode pack 68, that may be utilized in probesystems 10, according to the present disclosure.

Diode pack 68 of FIG. 3 may include and/or be a more detailedillustration of nonlinear circuitry 50 and/or of diode packs 68illustrated in FIGS. 1-2 and discussed herein with reference thereto. Assuch, any of the structures, functions, and/or features of diode packs68 of FIG. 3 may be included in and/or utilized with nonlinear circuitry50 and/or diode packs 68 of FIGS. 1-2 without departing from the scopeof the present disclosure. Similarly, any of the structures, functions,and/or features of probe systems 10, of nonlinear circuitry 50, and/ordiode packs 68 of FIGS. 1-2 may be included in and/or utilized withnonlinear circuitry 50 and/or diode packs 68 of FIG. 3 without departingfrom the scope of the present disclosure.

Diode pack 68 also may be referred to herein as a double back powerdiode 68 and/or as a double back power diode pack 68. Nonlinearcircuitry 50 and/or diode pack 68 may include a first terminal 61 and asecond terminal 62. Diode pack 68 also may include a plurality of diodes70, including a first diode 71 and a second diode 72. First diode 71electrically interconnects first terminal 61 and second terminal 62 at afirst diode polarity, and second diode 72 electrically interconnectsfirst terminal 61 and second terminal 62 at a second diode polarity. Thesecond diode polarity is different from, is opposed to, and/or isopposite the first diode polarity.

As such, one diode 70, such as first diode 71, permits electric current80 flow from first terminal 61 to second terminal 62 and resistselectric current flow from second terminal 62 to first terminal 61.Conversely, another diode 70, such as second diode 72, permits electriccurrent flow from second terminal 62 to first terminal 61 and resistselectric current flow from first terminal 61 to second terminal 62.

A magnitude of electric current 80 produced within ground loop 150 bymagnetic field M in the absence of diode pack 68 is expected to berelatively low, generally on the order of a few milliamps (mA).Similarly, a magnitude of a potential difference, or voltage, producedwithin ground loop 150 by magnetic field M also is expected to berelatively low, generally less than a millivolt (mV). These voltagevalues are significantly below a threshold voltage differential, or athreshold “turn-on” voltage, for silicon-based diodes (nominally 0.7volts) or for germanium-based diodes (nominally 0.3 volts).

Thus, and as illustrated in FIG. 5, diodes 70 of diode packs 68 functionas resistors, as nonlinear resistors, and/or as variable resistors, witha resistance value, that is defined by the diodes, being dictated by thevoltage differential, or the forward-polarity voltage differential,across the diodes. As an example, when the forward-polarity voltagedifferential is 0.3 V, FIG. 5 indicates that the diode current will beapproximately 2-3 microamps and the diode resistance will beapproximately 80-90 kohms. Thus, at the low voltages produced bymagnetic field M, electric current flow within the ground loop is nearlyeliminated by diode packs 68.

It is noteworthy, however, that a significant function of ground loop150 and/or of the various electrical conductors that define ground loop150 is to protect a user of probe system 10 from electrical shock. Diodepacks 68 also facilitate this functionality. More specifically, when theforward-polarity voltage differential across the diode pack is greaterthan the threshold voltage differential, the diode resistance becomesquite small, thereby permitting dissipation of potentially dangerouselectric currents. Returning to FIG. 5, for forward-polarity diodevoltages above approximately 0.7 V, in the case of a silicon-baseddiode, the diode resistance is approximately 20 ohms. This dioderesistance decreases to less than 2 ohms for forward-polarity diodevoltages above approximately 2.0 volts.

FIG. 5 illustrates one example of current and resistance vs. voltage fordiodes 70 that may be utilized within diode packs 68 of nonlinearcircuitry 50. However, and as discussed, nonlinear circuitry 50 mayinclude any suitable structure, element, and/or elements that exhibit anonlinear current vs. voltage curve, such as the nonlinear current vs.voltage curve that is illustrated in FIG. 5. With this in mind,nonlinear circuitry 50 may be configured such that the threshold voltagedifferential has any suitable value. As examples, the threshold voltagedifferential may be at least 0.1 volts (V), at least 0.2 V, at least 0.3V, at least 0.4 V, at least 0.5 V, at least 0.6 V, at least 0.7 V, atleast 0.8 V, at least 0.9 V, and/or at least 1 V. Additionally oralternatively, the threshold voltage differential may be at most 5 V, atmost 4.5 V, at most 4 V, at most 3.5 V, at most 3 V, at most 2.5 V, atmost 2 V, at most 1.5 V, at most 1 V, at most 0.9 V, at most 0.8 V, atmost 0.7 V, at most 0.6 V, at most 0.5 V, and/or at most 0.4 V.

When the voltage differential across nonlinear circuitry 50 is less thanthe threshold voltage differential, the nonlinear circuitry may beconfigured to provide a threshold low-voltage resistance thereacrossand/or between first terminal 61 and second terminal 62. Examples of thethreshold low-voltage resistance include resistances of at least 50ohms, at least 75 ohms, at least 100 ohms, at least 125 ohms, at least150 ohms, at least 175 ohms, at least 200 ohms, at least 250 ohms, atleast 300 ohms, at least 400 ohms, at least 500 ohms, at least 600 ohms,at least 700 ohms, at least 800 ohms, at least 900 ohms, at least 1000ohms, at least 1250 ohms, at least 1500 ohms, at least 1750 ohms, and/orat least 2000 ohms.

Additionally or alternatively, when the voltage differential acrossnonlinear circuitry 50 is greater than the threshold voltagedifferential, the nonlinear circuitry may be configured to provide athreshold high-voltage resistance thereacross and/or between firstterminal 61 and second terminal 62. Examples of the thresholdhigh-voltage resistance include resistances of at most 100 ohms, at most50 ohms, at most 25 ohms, at most 20 ohms, at most 15 ohms, at most 10ohms, at most 5 ohms, at most 2.5 ohms, at most 1 ohm, and/or at most0.5 ohms.

Stated another way, nonlinear circuitry 50 may define at least thethreshold low-voltage resistance when the voltage differential acrossthe nonlinear circuitry is less than the threshold voltage differential,and nonlinear circuitry may define the threshold high-voltage resistancewhen the voltage differential across the nonlinear circuitry is greaterthan the threshold voltage differential. The threshold low-voltageresistance may be greater than the threshold high-voltage resistance. Asan example, the threshold low-voltage resistance may be a thresholdresistance multiple of the threshold high-voltage resistance. Examplesof the threshold resistance multiple include at least 100, at least 500,at least 1000, at least 2500, at least 5000, at least 7500, at least10,000, at least 25,000, at least 50,000, at least 75,000, or at least100,000.

Returning to FIG. 1, probe systems 10 may include any suitable number ofstructures 20 that include at least first structure 21 and secondstructure 22. As an example, and as illustrated in dashed lines, probesystem 10 additionally may include a third structure 23. In thisexample, third structure 23 may be electrically connected to the groundpotential via a third structure ground conductor 33. Also in thisexample, probe system 10 may include a first intermediate groundconductor 41, which electrically interconnects first structure 21 andsecond structure 22, and a second intermediate ground conductor 42,which electrically interconnects second structure 22 and third structure23.

In such a configuration, probe system 10 may define a plurality ofground loops 150. More specifically, probe system 10 may define a firstground loop 151, as illustrated in solid lines in FIG. 1, a secondground loop 152, as illustrated in dashed lines in FIG. 1, and a thirdground loop 153, as illustrated in dash-dot lines in FIG. 1.

First ground loop 151 may be at least partially defined by firststructure ground conductor 31, first structure 21, first intermediateground conductor 41, second structure 22, and second structure groundconductor 32. Second ground loop 152 may be at least partially definedby second structure ground conductor 32, second structure 22, secondintermediate ground conductor 42, third structure 23, and thirdstructure ground conductor 33. Third ground loop 153 may be at leastpartially defined by first structure ground conductor 31, firststructure 21, first intermediate ground conductor 41, second structure22, second intermediate ground conductor 42, third structure 23, andthird structure ground conductor 33.

A facilities ground conductor 140 may provide the ground potential. Insuch a configuration, structure ground conductors 30 may be electricallyconnected to the facilities ground conductor and/or the facilitiesground conductor may define a portion of first ground loop 151, secondground loop 152, and/or third ground loop 153. As examples, thefacilities ground conductor may define a portion of the respectiveground loop that extends between first structure ground conductor 31 andsecond structure ground conductor 32, between second structure groundconductor 32 and third structure ground conductor 33, and/or betweenfirst structure ground conductor 31 and third structure ground conductor33.

It is within the scope of the present disclosure that each ground loop150 defined by probe system 10 may include nonlinear circuitry 50.Nonlinear circuitry 50 may be positioned at any suitable, or convenient,location within the ground loop. As examples, and as illustrated in FIG.1, nonlinear circuitry 50 may be electrically connected to, may form aportion of, and/or may be associated with first structure groundconductor 31, as indicated at 51, second structure ground conductor 32,as indicated at 53, and/or third structure ground conductor 33, asindicated at 55.

It is within the scope of the present disclosure that structures 20,including first structure 21, second structure 22, and/or thirdstructure 23, when present, may include, be, and/or be at leastpartially defined by any suitable component of probe systems 10. Asexamples, structures 20 may include one or more of an enclosure thatdefines an enclosed volume configured to contain the DUT, a chuck thatdefines a support surface configured to support the DUT, atemperature-controlled chuck, a probe assembly that includes at leastone probe configured to communicate with the DUT, a test instrument, asignal generation and analysis assembly, a temperature controller of theprobe system, a chiller of the probe system, a material handling robotof the probe system, and/or a wafer handler.

The probe assembly, when present, may include and/or be an electricalprobe assembly including at least one electrical probe configured toelectrically communicate with the DUT and/or an optical probe assemblythat includes at least one optical probe configured to opticallycommunicate with the DUT. The signal generation and analysis assembly,when present, may be configured to provide a test signal to the DUTand/or to receive a resultant signal from the DUT.

The test instrument, when present, may be provided with probe system 10and/or by a manufacturer of probe system 10. Additionally oralternatively, the test instrument may be provided by a user, or anend-user, of probe system 10. Examples of the test instrument includemeasurement instruments and/or other related equipment. With this inmind, nonlinear circuitry 50, according to the present disclosure, maybe utilized to flexibly and/or modularly decrease ground loop currentand/or associated electrical noise in probe systems that include anysuitable number of manufacturer and/or user-supplied structures 20 thatform and/or define corresponding ground loops 150.

In a specific example, and as illustrated schematically in FIG. 2 andless schematically in FIG. 4, first structure 21 may include anenclosure 100 that defines an enclosed volume 102 configured to containa DUT 92 that may be formed on a substrate 90. In this example, secondstructure 22 may include a test instrument 130, such as a signalgeneration and analysis assembly 132, configured to electrically testthe DUT. Enclosure 100 may be electrically connected to a groundpotential, such as to facilities ground conductor 140, via firststructure ground conductor 31. Enclosure 100 also may be electricallyconnected to test instrument 130 via intermediate ground conductor 40,and test instrument 130 may be electrically connected to the groundpotential via second structure ground conductor 32. In this example,probe system 10 also may include a chuck 110 that defines a supportsurface 112 configured to support the substrate and/or a probe assembly120 that includes at least one probe 122 configured to provide a testsignal to the DUT and/or to receive a resultant signal from the DUT. Asillustrated in FIG. 4, intermediate ground conductor 40 may beconfigured to shield, or to electrically shield, a signal conductor 124,which may be configured to convey a test signal and/or a resultantsignal between test instrument 130 and probe 122.

In such a configuration, ground loop 150 may be formed at least by firststructure ground conductor 31, enclosure 100, intermediate groundconductor 40, test instrument 130, and second structure ground conductor32. Also in such a configuration, nonlinear circuitry 50 may be includedwithin the ground loop. As discussed in more detail herein, inclusion ofnonlinear circuitry 50 within the ground loop may decrease a magnitudeof electric current flow within the ground loop, such as may be causedby magnetic field M. This may decrease electrical noise within enclosedvolume 102 and/or proximate DUT 92, thereby decreasing noise inelectrical measurements that may be performed by the probe system.

DUT 92 may include any suitable structure that may be tested by probesystem 10 and/or that may be defined by, defined on, defined in, and/orsupported by substrate 90. Examples of DUT 92 include a solid statedevice, a semiconductor device, a logic device, a transistor, a memorydevice, an imaging device, a complementary metal oxide semiconductor(CMOS) imaging device, and/or a charge coupled device (CCD) sensor.Examples of substrate 90 include a semiconductor wafer, a silicon wafer,a gallium arsenide wafer, and/or a Group III-V semiconductor wafer.

FIG. 6 is a flowchart depicting examples of methods 200 of testing adevice under test utilizing probe systems, according to the presentdisclosure. Methods 200 include positioning a device under test (DUT) at210 and resisting electric current flow at 220. Methods 200 may includeexciting a ground loop at 230. Methods 200 include permitting electriccurrent flow in the ground loop at 240. Methods 200 further may includetesting operation of the DUT at 250.

Positioning the device under test (DUT) at 210 may include positioningthe device under test in and/or within a probe system. The probe systemmay include an electrically conductive ground loop and nonlinearcircuitry that may be electrically connected to the electricallyconductive ground loop. Examples of the probe system are disclosedherein with reference to probe systems 10. Examples of the electricallyconductive ground loop and of the nonlinear circuitry are disclosedherein with reference to ground loops 150 and nonlinear circuitry 50,respectively.

Resisting electric current flow at 220 may include resisting electriccurrent flow within the ground loop and/or with the nonlinear circuitry.The resisting at 220 also may include resisting the electric currentflow when a voltage differential across the nonlinear circuitry, withinthe ground loop, is less than a threshold voltage differential, if thevoltage differential is less than the threshold voltage differential,and/or responsive to the voltage differential being less than thethreshold voltage differential. Additionally or alternatively, theresisting at 220 may include defining and/or establishing at least athreshold low-voltage resistance within the nonlinear circuitry and/orwithin the ground loop via the nonlinear circuitry. Examples of thethreshold voltage differential and the threshold low-voltage resistanceare disclosed herein.

The resisting at 220 may be performed with any suitable timing and/orsequence during methods 200. As examples, the resisting at 220 may beperformed prior to the permitting at 240, subsequent to the permittingat 240, and/or during the testing at 250.

Exciting the ground loop at 230 may include exciting the ground loopsuch that the voltage differential across the nonlinear circuitry isgreater than the threshold voltage differential and may be accomplishedin any suitable manner. As an example, the probe system may bepositioned within an environment that includes a magnetic field, and themagnetic field may induce an electric current flow within the groundloop. The magnetic field may be emitted by one or more components ofprobe system 10 and/or by other pieces of equipment that may be externalto probe system 10 and/or within the environment.

Permitting electric current flow in the ground loop at 240 may includepermitting the electric current flow through and/or within the nonlinearcircuitry. This may include permitting the electric current flow whenthe voltage differential across the nonlinear circuitry is greater thanthe threshold voltage differential, if the voltage differential isgreater than the threshold voltage differential, and/or responsive tothe voltage differential being greater than the threshold voltagedifferential. Additionally or alternatively, the permitting at 240 mayinclude defining and/or establishing at most a threshold high-voltageresistance within the nonlinear circuitry and/or within the ground loopvia the non-linear circuitry. Examples of the threshold high-voltageresistance are disclosed herein. In some examples, the thresholdlow-voltage resistance may be greater than the threshold high-voltageresistance and/or may be a threshold multiple of the thresholdhigh-voltage resistance. Examples of the threshold multiple aredisclosed herein.

The permitting at 240 may be performed with any suitable timing and/orsequence during methods 200. As examples, the permitting at 240 may beperformed subsequent to the resisting at 220, prior to the resisting at220, subsequent to the exciting at 230, responsive to the exciting at230, and/or during the testing at 250.

Testing operation of the DUT at 250 may include testing any suitableoperation and/or parameter of the DUT in any suitable manner. As anexample, the testing at 250 may include providing a test signal to theDUT. As another example, the testing at 250 may include receiving aresultant signal from the DUT. As discussed in more detail herein, thetest signal may include and/or be any suitable electrical and/or opticaltest signal. Similarly, the resultant signal may include and/or be anysuitable electrical and/or optical resultant signal.

In some examples, probe systems 10 may be referred to herein as beingutilized in and/or as part of a method of testing, or of electricallytesting, DUT 92. Such methods may include positioning the DUT within theprobe system, such as on support surface 112 of FIG. 2. Such methodsalso may include resisting electric current flow within the ground loop,such as ground loop 150 of FIGS. 1-2. The resisting may includeresisting with nonlinear circuitry, such as nonlinear circuitry 50 ofFIGS. 1-3. The methods further may include testing the operation of theDUT, such as by providing a test signal to the DUT and/or receiving aresultant signal from the DUT. The test signal may be provided by a testinstrument, such as test instrument 130 of FIG. 2, and/or the resultantsignal may be received by the test instrument.

In the present disclosure, several of the illustrative, non-exclusiveexamples have been discussed and/or presented in the context of flowdiagrams, or flow charts, in which the methods are shown and describedas a series of blocks, or steps. Unless specifically set forth in theaccompanying description, it is within the scope of the presentdisclosure that the order of the blocks may vary from the illustratedorder in the flow diagram, including with two or more of the blocks (orsteps) occurring in a different order and/or concurrently. It is alsowithin the scope of the present disclosure that the blocks, or steps,may be implemented as logic, which also may be described as implementingthe blocks, or steps, as logics. In some applications, the blocks, orsteps, may represent expressions and/or actions to be performed byfunctionally equivalent circuits or other logic devices. The illustratedblocks may, but are not required to, represent executable instructionsthat cause a computer, processor, and/or other logic device to respond,to perform an action, to change states, to generate an output ordisplay, and/or to make decisions.

As used herein, the term “and/or” placed between a first entity and asecond entity means one of (1) the first entity, (2) the second entity,and (3) the first entity and the second entity. Multiple entities listedwith “and/or” should be construed in the same manner, i.e., “one ormore” of the entities so conjoined. Other entities may optionally bepresent other than the entities specifically identified by the “and/or”clause, whether related or unrelated to those entities specificallyidentified. Thus, as a non-limiting example, a reference to “A and/orB,” when used in conjunction with open-ended language such as“comprising” may refer, in one embodiment, to A only (optionallyincluding entities other than B); in another embodiment, to B only(optionally including entities other than A); in yet another embodiment,to both A and B (optionally including other entities). These entitiesmay refer to elements, actions, structures, steps, operations, values,and the like.

As used herein, the phrase “at least one,” in reference to a list of oneor more entities should be understood to mean at least one entityselected from any one or more of the entities in the list of entities,but not necessarily including at least one of each and every entityspecifically listed within the list of entities and not excluding anycombinations of entities in the list of entities. This definition alsoallows that entities may optionally be present other than the entitiesspecifically identified within the list of entities to which the phrase“at least one” refers, whether related or unrelated to those entitiesspecifically identified. Thus, as a non-limiting example, “at least oneof A and B” (or, equivalently, “at least one of A or B,” or,equivalently “at least one of A and/or B”) may refer, in one embodiment,to at least one, optionally including more than one, A, with no Bpresent (and optionally including entities other than B); in anotherembodiment, to at least one, optionally including more than one, B, withno A present (and optionally including entities other than A); in yetanother embodiment, to at least one, optionally including more than one,A, and at least one, optionally including more than one, B (andoptionally including other entities). In other words, the phrases “atleast one,” “one or more,” and “and/or” are open-ended expressions thatare both conjunctive and disjunctive in operation. For example, each ofthe expressions “at least one of A, B, and C,” “at least one of A, B, orC,” “one or more of A, B, and C,” “one or more of A, B, or C,” and “A,B, and/or C” may mean A alone, B alone, C alone, A and B together, A andC together, B and C together, A, B, and C together, and optionally anyof the above in combination with at least one other entity.

In the event that any patents, patent applications, or other referencesare incorporated by reference herein and (1) define a term in a mannerthat is inconsistent with and/or (2) are otherwise inconsistent with,either the non-incorporated portion of the present disclosure or any ofthe other incorporated references, the non-incorporated portion of thepresent disclosure shall control, and the term or incorporateddisclosure therein shall only control with respect to the reference inwhich the term is defined and/or the incorporated disclosure was presentoriginally. As used herein the terms “adapted” and “configured” meanthat the element, component, or other subject matter is designed and/orintended to perform a given function. Thus, the use of the terms“adapted” and “configured” should not be construed to mean that a givenelement, component, or other subject matter is simply “capable of”performing a given function but that the element, component, and/orother subject matter is specifically selected, created, implemented,utilized, programmed, and/or designed for the purpose of performing thefunction. It is also within the scope of the present disclosure thatelements, components, and/or other recited subject matter that isrecited as being adapted to perform a particular function mayadditionally or alternatively be described as being configured toperform that function, and vice versa.

As used herein, the phrase, “for example,” the phrase, “as an example,”and/or simply the term “example,” when used with reference to one ormore components, features, details, structures, embodiments, and/ormethods according to the present disclosure, are intended to convey thatthe described component, feature, detail, structure, embodiment, and/ormethod is an illustrative, non-exclusive example of components,features, details, structures, embodiments, and/or methods according tothe present disclosure. Thus, the described component, feature, detail,structure, embodiment, and/or method is not intended to be limiting,required, or exclusive/exhaustive; and other components, features,details, structures, embodiments, and/or methods, including structurallyand/or functionally similar and/or equivalent components, features,details, structures, embodiments, and/or methods, are also within thescope of the present disclosure.

As used herein, “at least substantially,” when modifying a degree orrelationship, may include not only the recited “substantial” degree orrelationship, but also the full extent of the recited degree orrelationship. A substantial amount of a recited degree or relationshipmay include at least 75% of the recited degree or relationship. Forexample, an object that is at least substantially formed from a materialincludes objects for which at least 75% of the objects are formed fromthe material and also includes objects that are completely formed fromthe material. As another example, a first length that is at leastsubstantially as long as a second length includes first lengths that arewithin 75% of the second length and also includes first lengths that areas long as the second length.

Illustrative, non-exclusive examples of probe systems and methodsaccording to the present disclosure are presented in the followingenumerated paragraphs. It is within the scope of the present disclosurethat an individual step of a method recited herein, including in thefollowing enumerated paragraphs, may additionally or alternatively bereferred to as a “step for” performing the recited action.

A1. A probe system for testing a device under test (DUT), the probesystem comprising:

an electrically conductive ground loop;

a structure electrically connected to a ground potential via at least aregion of the electrically conductive ground loop; and

nonlinear circuitry electrically connected to the electricallyconductive ground loop, optionally wherein the nonlinear circuitry isconfigured to at least one of:

(i) resist flow of electric current within the electrically conductiveground loop when a voltage differential across the nonlinear circuitryis less than a threshold voltage differential;

(ii) permit flow of electric current within the electrically conductiveground loop when the voltage differential across the nonlinear circuitryis greater than the threshold voltage differential;

(iii) define at least a threshold low-voltage resistance when thevoltage differential across the nonlinear circuitry is less than thethreshold voltage differential; and

(iv) define at most a threshold high-voltage resistance when the voltagedifferential across the nonlinear circuitry is greater than thethreshold voltage differential.

A2. The probe system of paragraph A1, wherein the threshold low-voltageresistance is greater than the threshold high-voltage resistance.

A3. The probe system of any of paragraphs A1-A2, wherein the thresholdlow-voltage resistance is a threshold resistance multiple of thethreshold high-voltage resistance, wherein the threshold resistancemultiple is at least 100, at least 500, at least 1000, at least 2500, atleast 5000, at least 7500, at least 10,000, at least 25,000, at least50,000, at least 75,000, or at least 100,000.

A4. The probe system of any of paragraphs A1-A3, wherein:

the structure is a first structure and is electrically connected to theground potential via a first structure ground conductor;

the probe system further includes a second structure electricallyconnected to the ground potential via a second structure groundconductor;

the probe system further includes an intermediate ground conductor thatelectrically interconnects the first structure and the second structure;and

the first structure, the first structure ground conductor, the secondstructure, the second structure ground conductor, the intermediateground conductor, and the nonlinear circuitry at least partially definethe electrically conductive ground loop.

A5. The probe system of any of paragraphs A1-A4, wherein the nonlinearcircuitry includes at least one of:

(i) a diode pack;

(ii) a double back power diode pack;

(iii) a power transistor with included voltage-sensitive device;

(iv) a power MOFSET with included voltage-sensitive device; and

(v) a transient voltage suppressor (TVS).

A6. The probe system of any of paragraphs A1-A5, wherein the nonlinearcircuitry includes:

(i) a first terminal; and

(ii) a second terminal;

(iii) optionally a first diode that electrically interconnects the firstterminal and the second terminal at a first diode polarity; and

(iv) optionally a second diode that electrically interconnects the firstterminal and the second terminal at a second diode polarity that isopposite the first diode polarity.

A7. The probe system of paragraph A6, wherein the nonlinear circuitry isconfigured to:

(i) resist flow of electric current within the electrically conductiveground loop when a voltage differential between the first terminal andthe second terminal is less than the threshold voltage differential; and

(ii) permit the flow of electric current within the electricallyconductive ground loop when the voltage differential between the firstterminal and the second terminal is greater than the threshold voltagedifferential.

A8. The probe system of any of paragraphs A1-A7, wherein the thresholdvoltage differential is at least one of:

(i) at least 0.1 volts (V), at least 0.2 V, at least 0.3 V, at least 0.4V, at least 0.5 V, at least 0.6 V, at least 0.7 V, at least 0.8 V, atleast 0.9 V, or at least 1 V; and

(ii) at most 5 V, at most 4.5 V, at most 4 V, at most 3.5 V, at most 3V, at most 2.5 V, at most 2 V, at most 1.5 V, at most 1 V, at most 0.9V, at most 0.8 V, at most 0.7 V, at most 0.6 V, at most 0.5 V, or atmost 0.4 V.

A9. The probe system of any of paragraphs A6-A8, wherein the nonlinearcircuitry is configured to provide the threshold low-voltage resistancebetween the first terminal and the second terminal when the voltagedifferential is less than the threshold voltage differential.

A10. The probe system of any of paragraphs A1-A9, wherein the thresholdlow-voltage resistance is at least 50 ohms, at least 75 ohms, at least100 ohms, at least 125 ohms, at least 150 ohms, at least 175 ohms, atleast 200 ohms, at least 250 ohms, at least 300 ohms, at least 400 ohms,at least 500 ohms, at least 600 ohms, at least 700 ohms, at least 800ohms, at least 900 ohms, at least 1000 ohms, at least 1250 ohms, atleast 1500 ohms, at least 1750 ohms, or at least 2000 ohms.

A11. The probe system of any of paragraphs A6-A10, wherein the nonlinearcircuitry is configured to provide the threshold high-voltage resistancebetween the first terminal and the second terminal when the voltagedifferential is greater than the threshold voltage differential.

A12. The probe system of any of paragraphs A1-A11, wherein the thresholdhigh-voltage resistance is at most 100 ohms, at most 50 ohms, at most 25ohms, at most 20 ohms, at most 15 ohms, at most 10 ohms, at most 5 ohms,at most 2.5 ohms, at most 1 ohm, or at most 0.5 ohms.

A13. The probe system of any of paragraphs A1-A12, wherein at least oneof the structure, a/the first structure, and a/the second structureincludes at least one of:

(i) an enclosure that defines an enclosed volume configured to containthe DUT;

(ii) a chuck that defines a support surface configured to support theDUT;

(iii) a temperature-controlled chuck;

(iv) a probe assembly including at least one probe configured tocommunicate with the DUT;

(v) a test instrument;

(vi) a signal generation and analysis assembly configured to at leastone of provide a test signal to the DUT and receive a resultant signalfrom the DUT;

(vii) a temperature controller of the probe system;

(viii) a chiller of the probe system;

(ix) a material handling robot of the probe system; and

(x) a wafer handler.

A14. The probe system of any of paragraphs A1-A13, wherein the DUT isdefined on a substrate, optionally wherein the probe system includes thesubstrate.

A15. The probe system of paragraph A14, wherein the substrate includesat least one of a semiconductor wafer, a silicon wafer, a galliumarsenide wafer, and a Group III-V semiconductor wafer.

A16. The probe system of any of paragraphs A1-A15, wherein the DUTincludes at least one of:

(i) a solid state device;

(ii) a semiconductor device;

(iii) a logic device;

(iv) a transistor;

(v) a memory device;

(vi) an imaging device;

(vii) a complementary metal oxide semiconductor (CMOS) imaging device;and/or

(viii) a charge coupled device (CCD) sensor.

A17. The probe system of any of paragraphs A1-A16, wherein the probesystem includes the DUT.

A18. The probe system of any of paragraphs A1-A17 when dependent fromparagraph A4, wherein the first structure includes an/the enclosure,wherein the enclosure defines an/the enclosed volume configured tocontain the DUT.

A19. The probe system of paragraph A18, wherein the probe system furtherincludes a/the chuck that defines a/the support surface configured tosupport the DUT.

A20. The probe system of any of paragraphs A18-A19, wherein the secondstructure includes a test instrument configured to electrically test theDUT.

A21. The probe system of paragraph A20, wherein the test instrumentincludes a/the signal generation and analysis assembly.

A22. The probe system of any of paragraphs A18-A21, wherein the probesystem further includes a/the probe assembly configured to at least oneof provide a/the test signal to the DUT and receive a/the resultantsignal from the DUT.

A23. The probe system of any of paragraphs A1-A12, wherein the groundpotential is defined by a facilities ground conductor.

A24. The probe system of paragraph A23 when dependent from paragraph A4,wherein at least one of:

(i) the first structure ground conductor is electrically connected tothe facilities ground conductor; and

(ii) the second structure ground conductor is electrically connected tothe facilities ground conductor.

A25. The probe system of any of paragraphs A23-A24 when dependent fromparagraph A4, wherein the first structure, the first structure groundconductor, the second structure, the second structure ground conductor,the intermediate ground conductor, the facilities ground conductor, andthe nonlinear circuitry at least partially define the electricallyconductive ground loop.

A26. The probe system of any of paragraphs A1-A25, wherein the probesystem further includes at least one of:

(i) a/the first structure ground conductor;

(ii) a/the second structure ground conductor; and

(iii) a/the facilities ground conductor.

B1. A method of testing a device under test (DUT), the methodcomprising:

positioning the DUT within a probe system, wherein the probe systemincludes an electrically conductive ground loop and nonlinear circuitryelectrically connected to the electrically conductive ground loop;

resisting electric current flow within the electrically conductiveground loop, with the nonlinear circuitry, when a voltage differentialacross the nonlinear circuitry is less than a threshold voltagedifferential; and permitting electric current flow within theelectrically conductive ground loop and through the nonlinear circuitrywhen the voltage differential across the nonlinear circuitry is greaterthan the threshold voltage differential.

B2. The method of paragraph B1, wherein the probe system includes anysuitable structure of any of the probe systems of any of paragraphsA1-A26.

B3. The method of any of paragraphs B1-B2, wherein the method furtherincludes exciting the electrically conductive ground loop such that thevoltage differential across the nonlinear circuitry is greater than thethreshold voltage differential.

B4. The method of any of paragraphs B1-B3, wherein the method furtherincludes at least one of:

(i) performing the resisting subsequent to the permitting; and

(ii) performing the permitting subsequent to the resisting.

B5. The method of any of paragraphs B1-B4, wherein the resistingincludes defining at least a threshold low-voltage resistance with thenonlinear circuitry.

B6. The method of any of paragraphs B1-B5, wherein the permittingincludes defining at most a threshold high-voltage resistance with thenonlinear circuitry.

B7. The method of paragraph B6 when dependent from paragraph B5, whereinthe threshold low-voltage resistance is greater than the thresholdhigh-voltage resistance.

B8. The method of any of paragraphs B6-B7 when dependent from paragraphB5, wherein the threshold low-voltage resistance is at least a thresholdresistance multiple of the threshold high-voltage resistance, whereinthe threshold resistance multiple is at least 100, at least 500, atleast 1000, at least 2500, at least 5000, at least 7500, at least10,000, at least 25,000, at least 50,000, at least 75,000, or at least100,000.

B9. The method of any of paragraphs B1-B8, wherein the method furtherincludes testing operation of the DUT.

B10. The method of paragraph B9, wherein the testing includes at leastone of:

(i) providing a test signal to the DUT; and

(ii) receiving a resultant signal from the DUT.

B11. The method of any of paragraphs B9-B10, wherein the method includesperforming the resisting during the testing.

B12. The method of any of paragraphs B9-B11, wherein the method includesperforming the permitting during the testing.

C1. The use of nonlinear circuitry, within a ground loop of a probesystem, to selectively permit and to selectively restrict electriccurrent flow within the ground loop.

INDUSTRIAL APPLICABILITY

The probe systems and methods disclosed herein are applicable to thesemiconductor test industry.

It is believed that the disclosure set forth above encompasses multipledistinct inventions with independent utility. While each of theseinventions has been disclosed in its preferred form, the specificembodiments thereof as disclosed and illustrated herein are not to beconsidered in a limiting sense as numerous variations are possible. Thesubject matter of the inventions includes all novel and non-obviouscombinations and subcombinations of the various elements, features,functions and/or properties disclosed herein. Similarly, where theclaims recite “a” or “a first” element or the equivalent thereof, suchclaims should be understood to include incorporation of one or more suchelements, neither requiring nor excluding two or more such elements.

It is believed that the following claims particularly point out certaincombinations and subcombinations that are directed to one of thedisclosed inventions and are novel and non-obvious. Inventions embodiedin other combinations and subcombinations of features, functions,elements and/or properties may be claimed through amendment of thepresent claims or presentation of new claims in this or a relatedapplication. Such amended or new claims, whether they are directed to adifferent invention or directed to the same invention, whetherdifferent, broader, narrower, or equal in scope to the original claims,are also regarded as included within the subject matter of theinventions of the present disclosure.

1. A probe system for testing a device under test (DUT), the probesystem comprising: an electrically conductive ground loop; a structureelectrically connected to a ground potential via at least a region ofthe electrically conductive ground loop; and nonlinear circuitryelectrically connected to the electrically conductive ground loop,wherein the nonlinear circuitry is configured to: (i) resist flow ofelectric current within the electrically conductive ground loop when avoltage differential across the nonlinear circuitry is less than athreshold voltage differential; and (ii) permit flow of electric currentwithin the electrically conductive ground loop when the voltagedifferential across the nonlinear circuitry is greater than thethreshold voltage differential.
 2. The probe system of claim 1, whereinthe nonlinear circuitry is configured to: (i) define at least athreshold low-voltage resistance when the voltage differential acrossthe nonlinear circuitry is less than the threshold voltage differential;and (ii) define at most a threshold high-voltage resistance when thevoltage differential across the nonlinear circuitry is greater than thethreshold voltage differential, wherein the threshold low-voltageresistance is greater than the threshold high-voltage resistance.
 3. Theprobe system of claim 2, wherein the threshold low-voltage resistance isa threshold resistance multiple of the threshold high-voltageresistance, wherein the threshold resistance multiple is at least 100.4. The probe system of claim 1, wherein: (i) the structure is a firststructure and is electrically connected to the ground potential via afirst structure ground conductor; (ii) the probe system further includesa second structure electrically connected to the ground potential via asecond structure ground conductor; (iii) the probe system furtherincludes an intermediate ground conductor that electricallyinterconnects the first structure and the second structure; and (iv) thefirst structure, the first structure ground conductor, the secondstructure, the second structure ground conductor, the intermediateground conductor, and the nonlinear circuitry at least partially definethe electrically conductive ground loop.
 5. The probe system of claim 4,wherein: (i) the first structure includes an enclosure, wherein theenclosure defines an enclosed volume configured to contain the DUT; and(ii) wherein the second structure includes a test instrument configuredto electrically test the DUT.
 6. The probe system of claim 5, whereinthe probe system further includes: (i) a chuck that defines a supportsurface configured to support the DUT; and (ii) a probe assemblyconfigured to at least one of provide a test signal to the DUT andreceive a resultant signal from the DUT.
 7. The probe system of claim 5,wherein the test instrument includes a signal generation and analysisassembly.
 8. The probe system of claim 1, wherein the nonlinearcircuitry includes at least one of: (i) a diode pack; (ii) a double backpower diode pack; (iii) a power transistor with includedvoltage-sensitive device; (iv) a power MOFSET with includedvoltage-sensitive device; and (v) a transient voltage suppressor (TVS).9. The probe system of claim 1, wherein the nonlinear circuitry includesa diode pack, wherein the diode pack includes: (i) a first terminal;(ii) a second terminal; (iii) a first diode that electricallyinterconnects the first terminal and the second terminal at a firstdiode polarity; and (iv) a second diode that electrically interconnectsthe first terminal and the second terminal at a second diode polaritythat is opposite the first diode polarity.
 10. The probe system of claim1, wherein the nonlinear circuitry includes a first terminal and asecond terminal, and further wherein the nonlinear circuitry isconfigured to: (i) resist flow of electric current within theelectrically conductive ground loop when a voltage differential betweenthe first terminal and the second terminal is less than the thresholdvoltage differential; and (ii) permit the flow of electric currentwithin the electrically conductive ground loop when the voltagedifferential between the first terminal and the second terminal isgreater than the threshold voltage differential.
 11. The probe system ofclaim 10, wherein the nonlinear circuitry is configured to provide thethreshold low-voltage resistance between the first terminal and thesecond terminal when the voltage differential is less than the thresholdvoltage differential, and further wherein the threshold low-voltageresistance is at least 500 ohms.
 12. The probe system of claim 10,wherein the nonlinear circuitry is configured to provide the thresholdhigh-voltage resistance between the first terminal and the secondterminal when the voltage differential is greater than the thresholdvoltage differential, and further wherein the threshold high-voltageresistance is at most 10 ohms.
 13. The probe system of claim 1, whereinthe structure includes at least one of: (i) an enclosure that defines anenclosed volume configured to contain the DUT; (ii) a chuck that definesa support surface configured to support the DUT; (iii) atemperature-controlled chuck; (iv) a probe assembly including at leastone probe configured to communicate with the DUT; (v) a test instrument;(vi) a signal generation and analysis assembly configured to at leastone of provide a test signal to the DUT and receive a resultant signalfrom the DUT; (vii) a temperature controller of the probe system; (viii)a chiller of the probe system; (ix) a material handling robot of theprobe system; and (x) a wafer handler.
 14. The probe system of claim 1,wherein the threshold voltage differential is at least 0.1 volts (V) andat most 5 V.
 15. A method of testing a device under test (DUT), themethod comprising: positioning the DUT within a probe system, whereinthe probe system includes an electrically conductive ground loop andnonlinear circuitry electrically connected to the electricallyconductive ground loop; resisting electric current flow within theelectrically conductive ground loop, with the nonlinear circuitry, whena voltage differential across the nonlinear circuitry is less than athreshold voltage differential; and permitting electric current flowwithin the ground loop and through the nonlinear circuitry when thevoltage differential across the nonlinear circuitry is greater than thethreshold voltage differential.
 16. The method of claim 15, wherein themethod further includes exciting the electrically conductive ground loopsuch that the voltage differential across the nonlinear circuitry isgreater than the threshold voltage differential.
 17. The method of claim15, wherein the method further includes at least one of: (i) performingthe resisting subsequent to the permitting; and (ii) performing thepermitting subsequent to the resisting.
 18. The method of claim 15,wherein: (i) the resisting includes defining at least a thresholdlow-voltage resistance with the nonlinear circuitry; and (ii) thepermitting includes defining at most a threshold high-voltage resistancewith the nonlinear circuitry, wherein the threshold low-voltageresistance is greater than the threshold high-voltage resistance. 19.The method of claim 18, wherein the threshold low-voltage resistance isat least a threshold resistance multiple of the threshold high-voltageresistance, and further wherein the threshold resistance multiple is atleast
 100. 20. The method of claim 15, wherein the method furtherincludes testing operation of the DUT, and further wherein the methodincludes: (i) performing the resisting during the testing; and (ii)performing the permitting during the testing.